Information from the Surveillance, Epidemiology, and End Results (SEER) Program merged with Medicare claims offers important insights into patterns of health care services, costs, and outcomes for Medicare beneficiaries with cancer. These findings have virtually exclusively pertained to Medicare recipient age 65 and older. However, Medicare covers more than 5 million disabled persons under age 65, with annual total costs exceeding $20 billion, and millions more, now over age 65, initially received Medicare because of disability. Despite these large numbers and high costs, disabled Medicare beneficiaries who develop cancer have received little attention. The primary purpose of the proposed project is to describe cancer diagnoses, initial treatments, palliative care, longevity, and costs to Medicare among older and younger Medicare beneficiaries with disabilities. Secondary goals are to compare cancer diagnoses, interventions, and clinical and cost outcomes between persons with and without disabilities. The project will examine four high-frequency diseases (lung, breast, colorectal, and prostate cancers), and it will use merged SEER-Medicare data from cases diagnosed from 1986 through 1999. Using diagnosis, stage, and treatment information from SEER and diagnosis and procedure codes and payment information from Medicare claims, this study will address questions across the continuum of care, from diagnosis to end of life. Questions include: whether persons with disabilities are diagnosed at later stages than non-disabled persons; whether initial treatments differ; whether all-cause and cancer-specific mortality rates differ; whether use of home care and hospice services differ; whether insurance type matters (fee-for-service versus managed care); and additional costs to Medicare when disabled beneficiaries develop cancer. This study will provide the first comprehensive information on cancer detection, care, costs, and outcomes among disabled Medicare beneficiaries. These findings may suggest areas where more attention is needed, such as increasing cancer screening among disabled Medicare recipients or rethinking initial treatment strategies.